A Rockwell Hardness Tester is a device used to measure the hardness of materials, particularly metals and plastics. It works by pressing a hard indenter into the material's surface under a specific load. The depth of the indentation left by the indenter is then measured, which allows for the determination of the material's hardness value. The Rockwell scale is commonly used in various industries to assess material properties. Different scales, such as Rockwell B and Rockwell C, are employed depending on the material type and hardness range. This testing method is valued for its speed and simplicity, making it a popular choice in quality control.